Michael, "Actually the first thing that I will be shooting for when I start to work on it will be to use the sequence list to have a persistent undo so you would keep the ability to undo beyond just the current active session. That will be the first target for the sequence storage and then editing coming sometime afterwards."

You mean we can undo not only last action but some actions beyond? If yes it would be great! Not real parametric but really handy feature. Because now for example it is so hard to remove/modify fillet and other stuff. But with this undo it will be great option to remove it.